Metabolic homeostasis via BDNF and its receptors

Abstract

Metabolic disorders result from dysregulation of central nervous system and peripheral metabolic energy homeostatic pathways. To maintain normal energy balance, neural circuits must integrate feedforward and feedback signals from the internal metabolic environment to orchestrate proper food intake and energy expenditure. These signals include conserved meal and adipocyte cues such as glucose and leptin, respectively, in addition to more novel players including brain-derived neurotrophic factor (BDNF). In particular, BDNF's two receptors, tropomyosin related kinase B (TrkB) and p75 neurotrophin receptor (p75NTR), are increasingly appreciated to be involved in whole body energy homeostasis. At times, these two receptors even seem to functionally oppose one another's actions, providing the framework for a potential neurotrophin mediated energy regulatory axis, which we explore further here.

Keywords: BDNF; TrkB; hypothalamus; metabolism; neurotrophins; p75NTR.

Figure 1:. Schematic representation of key hypothalamic regions and the expression of BDNF, p75NTR, and TrkB.

Arrows represent general connectivity between regions, and do not specify neurotrophin specific connections. Whether p75NTR and TrkB exist as independent or overlapping cell populations is unknown.